Rotary regenerator with rectangular matrix sections



June 23, 1970 5, TR ET AL 3,516,482

ROTARY REGENERATOR WITH RECTANGULAR MATRIX SECTIONS Filed Sept. 13, 1968 2 Shgets-Sheet 1 n 7 co 0 co w t- In f (\l qr com li analog GAS IN AIR OUT GAS IN INVENTORS. SALVATORE STRANITI FREDERICK MASSEY-SHN ATT RNEYS.

ROTARY REGENERATOR WITH RECTANGULAR MATRIX SECTIONS 2 Sheets-Sheet 2 June 1970 s. STRANITI ET AL Filed Sept. 15, 1968 United States Patent Int. Cl. F28d 19/04 US. Cl. 165-7 2 Claims ABSTRACT OF THE DISCLOSURE A heat exchanger is constructed with a plurality of rectangular sections of wire mesh, axially extending and radially supported matrices positioned within a rotating cylindrical drum. The matrices are retained diagonally within axial channels so that the axial flow of gases is directed transversely through each matrix.

THE PRIOR ART The prior art teaches several general types of rotary regenerators for use in conjunction with gas turbine engines. The disk type of rotary regenerator provides axial gas flow through the rotating disk type matrix. This permits face-type sealing which is generally regarded as advantageous because the extreme temperature changes which occur with each revolution of the matrix have relatively minor effect on the seal. However, the disk type of matrix requires a short axial length and hence a relatively large diameter for effective heat exchanging. In many gas turbine applications the diameter of the regenerator is limited, and disk type exchangers cannot be used.

The second type uses a rotating hollow cylindrical type matrix through which the fluid flows radially. This arrangement is advantageous in that an effective heat exchange area can be provided within a given diameter by increasing the axial dimension of the matrix to the extent necessary. However, the cylindrical matrix requires axial seals which are diflicult to maintain, particularly where large temperature gradients occur.

A third type of rotary regenerator is described in the US. patent to Straniti et al. 3,389,746 assigned to the same assignee as this invention. This patent discloses and claims a heat exchanger comprised of a plurality of concentrically positioned rotating cylindrical matrices, each of which is divided circumferentially into a plurality of segments. This construction has the advantage over a disktype matrix in that face-type seals may be used, and it has the advantage of the drum-type matrix in that a relativelysmall diameter is permitted.

SUMMARY OF THE INVENTION The present invention is an improvement over the Straniti et al. US. Pat. 3,389,746 in that it simplifies the construction of the regenerator by utilizing an axially short cylinder in which a plurality of rectangular matrices are radially positioned. This construction permits the use of face-type seals, and at the same time permits a relatively large heat exchange area.

OBJECTS It is an object of this invention to provide a rotary regenerator for exchanging the heat between two fluids, said exchanger being comprised of a plurality of radially disposed, axially extending matrices fixedly positioned within a rotating drum, the fluids flowing axially through the drum and transversely through the matrices, the sealing between the fluids being accomplished by face contact seals.

THE DRAWINGS FIG. 1 is a cross section of a preferred embodiment taken through the line 11 in FIG. 2;

FIG. 2 is an end view of the embodiment of FIG. 1 with certain portions broken away to illustrate interior details; and

FIG. 3 is a laid out section taken through the line 33 in FIG. 2.

THE PREFERRED EMBODIMENT The disclosed rotary regenerator is intended for use in combination with a gas turbine engine, the heat of the exhaust gases being exchanged with the heat of the intake airfor preheating the intake air prior to combustion.

The regenerator, generally indicated as 10, is rotatably supported by means of bearings 12 on a stationary hollow shaft 14. The regenerator 10 is comprised of a plurality of porous wire mesh matrices 16, each of which is positioned within a fluid impervious U-shaped channel 18. Each channel 18 is capped by a member 20 providing a conduit with open ends.

As shown in the drawings, the matrices 16 are disposed axially, "while the channels 18 are arranged at a small angle (approximately 15) with respect to the axis, so that the matrices are positioned diagonally with respect to the channels, as best seen in FIG. 3. An equivalent arrangement would be to position the channels axially with the matrices arranged at an angle to the axis. The arrangement as shown is advantageous for manufacturing purposes since it is less difficult and costly to form the sheet metal channels at an angle than to provide a complex form for the matrices. With either construction, any fluid flowing axially into one end of a conduit passes transversely through a diagonally disposed matrix 16 and exits axially at the opposite end. A plurality of the channels 18, with the matrices contained therein are joined circumferentially to form a complete annulus.

In effect, the regenerator consists of two concentric cylinders, the annular space between the cylinders being segmented into a plurality of generally axially extending fluid conduits, and with the radially disposed matrices being positioned diagonally within the channels.

The regenerator 10 is completed by flanged sealing plates 22 which are welded to each end of the annulus. The sealing plates 22 are provided with openings which match the open ends of the channels, but which cover the ends of the matrices 16.

The flanges 24 at the inside diameter of the sealing plates 22 incorporate the outer races of the bearings 12 which rotatably support the regenerator 10. The flange at the outer diameter of the sealing plates 22, located at the front of the regenerator, includes a ring gear 26 which is rotatably driven from a source (not shown).

The air and gas passages through the regenerator 10 are defined by annular seal carrier plates 28 and 30 located at the ends of the regenerator. The seal carrier plate 28 is provided with an air inlet opening 32 covering approximately 25% of the area of the annulus of the plate 28 and with a gas outlet opening 34 covering the remaining approximately 75% (less the space between the I openings). Similarly, the seal carrier plate 30 is provided with an air outlet opening 36 covering approximately 25% of the area of the annulus of the seal plate 30 and with a gas inlet opening 38 covering the remaining approximately of the area.

Cool air from the engine compressor is supplied to the regenerator 10 through the air inlet opening 32 from an annular duct 40 comprised of two cylindrical shells 42 and 44 which feed air to an inlet torus 46. The inlet torus 46 terminates at the air inlet opening 32 of the seal carrer plate 28 to which it is secured. The exhaust gases from the gas turbine engine are admitted through a duct 48 which terminates at the gas inlet opening 38 in the seal carrier plate 30. The air passing through the opening 32 in the seal carrier plate 28 passes through the matrices 16 and exits through the air outlet opening 36 into an air outlet conduit 50 defined by the space between the shell 44 and the duct 48. The exhaust gases entering the opening 38 from the duct 48 traverses the matrices 16 and exits through the gas outlet opening 34 into the atmosphere.

The compressed air entering at the air inlet 32 and exiting at the air outlet 36 is maintaained separate from the exhaust gases entering at the gas inlet 38 and exiting from the gas outlet 34 by means of face-type seals mounted on the seal carrier plates 28 and 30, respectively, The seals on both plates 28 and 30 are identical so that a description of one set will suffice. Each of the seal carrier plates 28 and 30 is provided with an inner and an outer circumferential groove in which circumferential seals 52 and 54 are positioned. Each of these seals is spring loaded by means of springs 56 and 58, respectively. The circumferential seals 52 and 54 are intersected by two pairs of radial seals 60 and 62 which are spring loaded by means of springs 64. Thus, the combination of the two pairs of radial seals and the two circumferential seals serves to entirely enclose both the air sector and the gas sector of the drums at each of the inlet and outlet openings.

In the alternative, the circumferential seals may terminate at the radial seals so that only the air sector is sealed. In such an embodiment, a simple spring leaf seal may surround the remaining sector. The exhaust gas leakage which may result with such a seal would simply be bypassed to the atmosphere, but overall operation would not be affected materially.

The space between the pair of seals 60 communicates with the space between the pair of seals 62 by means of transfer tubes 66 which serve to equalize the pressure loads of the gases at these locations. In addition, the transfer tubes 66 serve to reduce the carry-over loss of entrained air on the high pressure side by dumping this air into the low pressure side. These transfer tubes also serve to reduce the magnitude of any pressure pulse on the matrix assembly.

As noted before, the regenerator is carried on two bearings 12 supported on the hollow shaft 14. The hollow shaft 14 forms a structural tie between the inlet and outlet casings. The hollow shaft is shown closed by means of a circular closure wall 68. However, the wall may be pivoted by means of a crank 70 to permit the bypassing of the exhaust gases from the regenerator.

It will be apparent to persons skilled in the art that this invention is subject to various modifications and adaptations. It is intended therefore that the scope of the invention be limited only by the appended claims as interpreted in the light of the prior art.

We claim:

1. In a rotary heat exchanger for transferring the heat from a first fluid to a second fluid, the combination comprising:

a rotatably mounted fluid impervious structure having an annular cross section, the space between the inner and outer peripheries of said structure comprising a plurality of radially segmented conduits,

said conduits extending from one end of said structure to the other end at an angle with respect to the axis of rotation of said structure, said ends being open; i

a heat exchanging matrix in each of said conduits, each of said matrices extending radially and axially, said matrices being positioned diagonally across a respective conduit, where-by fluid flowing through said conduits passes transversely through each of said matrices;

a first fluid inlet duct and a first fluid outlet-duct, each having an opening communicating with first opposing segments at the ends of said structure;

a second fluid inlet duct and a second fluid outlet duct, each having an opening communicating with second opposing segments at the end of said structure;

sealing means for maintaining said first and second fluids separatedfsaid sealing means including one sealing element for the ducts at each end of said structure, said sealing elements being maintained in contact with a respective end of said structure, and wherein each sealing element comprises:

a seal carrier plate affixed across the openings of the ducts at one end of said structure, said plate having an opening coextensive with a respective segment;

an outer circular sealing element positioned on each plate;

an inner circular sealing element positioned on each plate adjacent the inner periphery thereof, said opening being located between said inner and outer circular sealing elements;

first and second spaced radial sealing elements on each plate, each intersecting said first and second circular sealing elements, adjacent one end of one opening;

third and fourth spaced radial sealing elements intersecting said first and seceond circular sealing elements adjacent the other end of said one opening; and

separate biasing means for each of said sealing elements for maintaining each of said sealing elements in contact with the respective ends of said structure.

2. The invention as defined in claim 1, and a fluid conduit communicating between the space between said first and second radial seals and the space between said second and third radial seals for equalizing the pressures in said spaces.

References Cited UNITED STATES PATENTS 2,607,565 8/1952 Jensen -9 2,757,907 8/1956 Williams 1659 3,010,704 11/1961 Egbert 1659 3,022,983 2/ 1962 Muller 1659 3,389,746 6/1968 Straniti 16510 3,409,073 11/1968 Botachik 1659 FOREIGN PATENTS 842,948 7/ 1952 Germany. 776,532 6/1957 Great Britain.

ROBERT A. OLEARY, Primary Examiner A. W. DAVIS, 111., Assistant Examiner US. Cl. X.R. 165-9, 10 

